Apparatus utilizing electric energy for processing of blood to neutralize pathogen cells therein

ABSTRACT

An operational unit for locating and neutralizing pathogen cells in blood. A cassette has a plurality of thin holding chambers that are filled with blood drawn from a patient. A light source illuminates each of the holding chambers and passes light to an underlying sensor array such that the cells in the blood produce shadow images of the cells in the sensor array. A processor performs pattern recognition to identify and locate the pathogen cells by use of an image library. After the pathogen cells are located, the pump is operated to move the identified cells to a processing zone. When each identified cell reaches the processing zone, electric energy is applied to destroy the identified pathogen cells. A pump refills the cassette holding chambers, returns the neutralized-pathogen blood to the patient, and the process is repeated for a treatment time period.

CROSS REFERENCE TO RELATED APPLICATIONS

Applicants have concurrently filed additional applications related to the subject matter of the present application. These are: Ser. No. 17/814,536 filed Jul. 25, 2022; Ser. No. 17/814,537 filed Jul. 25, 2022; Ser. No. 17/814,538 filed Jul. 25, 2022; Ser. No. 17/814,539 filed Jul. 25, 2022; Ser. No. 17/814,541 filed Jul. 25, 2022; Ser. No. 17/814,542 filed Jul. 25, 2022; Ser. No. 17/814,545 filed Jul. 25, 2022; Ser. No. 17/814,546 filed Jul. 25, 2022; Ser. No. 17/814,547 filed Jul. 25, 2022; Ser. No. 17/814,548 filed Jul. 25, 2022, and Ser. No. 17/814,549 filed Jul. 25, 2022.

BACKGROUND Field of the Invention

The present invention is in the field of biotechnology, semiconductor technology and further the medical field of treating individuals who have an infection of pathogen cells in the bloodstream.

Description of the Related Art

The presence of bacteria in human blood is a serious condition termed “bacteremia”. This condition can cause an infection that spreads through the bloodstream. This can also be termed “septicemia” which is defined as the invasion and persistence of pathogenic bacteria in the bloodstream. Such an infection can lead to a condition termed “sepsis” which is the body's reaction to the infection. Sepsis is a serious condition that can cause intense sickness including shock, and in some cases, can lead to the death of the infected person. A common pathogenic bacterium causing such infection is E. coli, but infections can also be caused by other pathogenic bacteria and organisms such as the fungus Candida auris. The usual treatment for the patient is the application of antibiotics to try to kill the pathogenic cells in the bloodstream. However, this treatment is not successful for many patients with a bloodstream infection.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view of an overall system which includes an operational unit and a system control unit,

FIG. 2 is a perspective view showing the interior of the enclosure 11 shown in FIG. 1 ,

FIG. 3 is an elevation, section view of components inside the operational unit shown in FIG. 1 ,

FIG. 4 is a plan view of the compression plate 51 shown in FIG. 3 ,

FIG. 5 is a bottom view of the light source shown in FIG. 3 with an array of light generators,

FIG. 6 is an elevation, sectional view of a collimated beam light generator, as shown in FIG. 5 ,

FIG. 7 is an elevation section view of the cassette 58 shown in FIG. 3 ,

FIG. 8 is a functional block diagram including additional components for the system shown in FIG. 1 ,

FIG. 9 is a top-down view illustrating the primary blood flow through the cassette 58 shown in FIG. 3

FIG. 10 is a section view along line 10-10 in FIG. 9 ,

FIG. 11 is a section view along line 11-11 in FIG. 9 ,

FIG. 12 is a is a section view along line 10-12 of FIG. 9 ,

FIG. 13 is a partial cutaway view of cassette 58, pump 62 and flow lines 22 and 24 shown in FIG. 3 ,

FIG. 14 is a top-down view of the top layer of the cassette 58, shown in FIG. 3 illustrating the flow of blood through the input manifold channels, holding chambers and output manifold channels,

FIG. 15 is a view of a cassette 58 holding chamber having a plurality of parallel ridges therein and multiple zones,

FIG. 16 is a section, perspective view of a portion of the cassette chamber shown in FIG. 15 ,

FIG. 17 is a top view of a portion of the cassette chamber shown in FIG. 15 ,

FIG. 18 is a section view of a portion of the cassette chamber shown in FIG. 15 together with a section view of a chamber driver,

FIG. 19 is a bottom view of hemispherical pads mounted on the driver shown in FIG. 18 ,

FIG. 20 is a top view of flat electrical connection pads shown in FIG. 18 ,

FIG. 21 is an electrical schematic block diagram of the chamber driver shown in FIG. 18 ,

FIG. 22 is a section perspective view of an alternate configuration to the structure shown in FIG. 16 at a portion of the cassette chamber shown in FIG. 14 ,

FIG. 23 is a top view of an alternate configuration to that shown in FIG. 17 for a portion of the cassette chamber shown in FIG. 14 ,

FIG. 24 is an electrical block diagram of the system shown in FIG. 1 ,

FIG. 25 is a top view of a light sensor array with control and data lines,

FIG. 26 is an electrical schematic of a 3T image sensor cell,

FIG. 27 is an electrical schematic of a 4T image sensor cell,

FIG. 28 is a top view of a layout of an image sensor cell,

FIG. 29 is a section view of a layout of an image sensor cell,

FIG. 30 is an illustration of cassette chamber zones used for physical calibration,

FIG. 31 is an illustration of a cassette chamber zone with a calibration marker,

FIG. 32 is a planar illustration of a portion of a sensor array illustrating physical calibration,

FIGS. 33A and 33B are a flow diagram illustrating a light source amplitude calibration process,

FIG. 34 is a set of pathogen image views for pattern recognition,

FIG. 35 is a set of red blood cell images for pattern recognition,

FIG. 36 is a set of white blood cell images for pattern recognition,

FIG. 37 is a set of platelet cell images for pattern recognition,

FIG. 38 is an illustration of blood flow in chamber channels for travel time calibration,

FIG. 39 is a travel time versus fluid velocity chart for travel time calibration,

FIGS. 40A, 40B and 40C are a logic flow diagram illustrating a travel time calibration process,

FIGS. 41A, 41B and 41C are a logic flow diagram illustrating an operational process to identify pathogen cells and move the identified cells to a processing zone in a chamber for neutralization, and

FIG. 42 illustrates electrical waveforms applied to electrodes in the channels of the processing zone of the chamber for neutralizing pathogen cells.

SUMMARY OF THE INVENTION

An embodiment of the present invention comprises an apparatus for first examining blood by imaging a first quantity of blood in a chamber to identify and locate pathogen cells in this quantity of blood. The pathogen cells thus identified are moved to a processing zone of the chamber and are then neutralized by the application of electric energy in the processing zones. The first quantity of blood, now processed, is then replaced with multiple subsequent quantities of blood and the process of identifying, locating and neutralizing pathogen cells is repeated for each quantity of blood. After these processing operations are performed repeatedly over a period of time, the count of viable pathogen cells in the patient blood is decreased.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is an apparatus for identifying pathogen cells in blood and neutralizing the identified cells to reduce the count of such cells in the blood and thereby potentially reducing the harmful effect of the pathogen cells to a patient.

Referring now to FIG. 1 , there is shown a system for processing blood which identifies and determines locations of individual pathogen cells in blood and then applies to located pathogen cells electric energy of sufficient magnitude to neutralize (kill) the identified pathogen cells. The applied energy is limited to a restricted region surrounding the identified pathogen cell such that nearby blood cells, such as erythrocytes (red blood cells), leukocytes (white blood cells) and platelets are subjected to little or no electric energy exposure.

The principal operations performed with the blood are carried out in an operational unit 10 which is connected by a data and control cable 12 to a system controller 14 which can be, for example, a laptop computer or computer work station. The operational unit 10 receives electrical power via a power line 16.

The operational unit 10 is connected to a patient 18 by means of a two-lumen (two fluid channels) catheter 20. In this example, the catheter 20 is inserted into an artery in the leg of patient 18 to both receive blood from the patient and return blood to the patient. The catheter 20 has one lumen thereof connected to a blood input line 22 which is connected to operational unit 10 and has a second lumen connected to a blood return line 24 which is also connected to the operational unit 10. The blood of patient 18 flows into the catheter 20, through input line 22 to the operational unit 10 and from the operational unit 10 through the return line 24 and catheter 20 back to the patient 18. A catheter, such as 20, is described in U.S. Pat. No. 6,872,198 issued Mar. 25, 2005 which patent is incorporated herein by reference in its entirety.

Within the operational unit 10 the blood is imaged to identify and locate pathogenic cells in the blood followed by neutralizing the located pathogenic cells at a subsequent location. This process continues over a period of time with a flow of blood from the patient with the goal of reducing the number of pathogenic cells in the patient's blood.

The operational unit 10 includes an enclosure 11 having a top lid 11 a which can be opened by use of a handle 11 b which rotates the lid 11 a on hinges 11 c. A thermal control unit 26, for example a heat pump, supplies heated or cooled air at a selected temperature through a duct 27 to the interior of the enclosure 11. The thermal control unit 26 is operated by the system controller 14 via a cable 28. The system controller 14 monitors temperature inside the enclosure 11 and controls the thermal control unit 26 to supply air to drive the temperature in the enclosure 11 to a preselected temperature or temperature range. The enclosure 11 has an opening 46 for passage therethrough of flow tubes and electrical conductors.

An embodiment of the invention described in the following text and corresponding drawings utilizes electric energy (applied as field or current) to neutralize located pathogen cells in blood. The electric energy is of sufficient intensity to kill the pathogen cells which have been located in the blood.

The interior of the enclosure 11, shown in FIG. 1 , is illustrated in FIG. 2 without operational components. A set of four rods 30, 32, 34 and 36 are mounted on the interior bottom surface of the enclosure 11. These rods project upward, perpendicular to the bottom surface of the enclosure 11. The top end of each of the rods 30, 32, 34 and 36 are threaded to receive respective nuts 38, 40, 42 and 44. The nuts 38, 40, 42 and 44, when mounted on the corresponding rods, engage the top surface of a compression plate 51 shown in FIGS. 3 and 4 . The enclosure 11 can include a thermostat and be connected to an air heater/cooler (see FIG. 8 ) to maintain the interior of the enclosure 11 within a selected temperature range to avoid thermal damage to the blood in the enclosure 11. Enclosure 11 has an opening 46 for passage of flow tubes and electrical cables.

A electric energy system of the present invention is shown in FIG. 1 , and described in the corresponding text, with specific internal components 50 of an operational unit 10 as shown in FIG. 3 . The operational unit 10 has multiple components 50 inside the enclosure 11. These components include the compression plate 51 and a light source 54. The unit 50 further includes a cassette 58 and an imager and processor unit 60. Line 22 extends through a pump 62 to the input of the cassette 58. Pump 62 draws blood from patient 18 through input line 22 into the operational unit 10 and the blood leaves unit 10 through return line 24 and through catheter 20 back to patient 18. The components 54, 58 and 60 have planar configurations and, in operation, are pressed together with limited spacing between them and secured by the nuts 38, 40, 42 and 44 to limit relative movement. The return line 24 is connected to the output port of cassette 58 and does not pass through the pump 62.

The compression plate 51 is shown in FIG. 4 . Plate 51 includes holes 72, 74, 76 and 78 which are positioned to receive the respective rods 30, 32, 34 and 36, see FIG. 2 . All of the elements 51, 54, 58 and 60 are provided with colinear holes for receiving the rods 30, 32, 34 and 36. When the nuts 38, 40, 42 and 44 are affixed to the rods 30, 32, 34 and 36, with all of the noted components 50 (see FIG. 3 ) in place and having the rods 30, 32, 34 and 36 passing therethrough, the nuts are tightened on the rods to cause the compression plate 51 to apply force to the stacked elements 51, 54, 58 and 60 to clamp them together and substantially limit relative movement, either horizontally or vertically, between these components.

A planar, bottom view of the light source 54 is shown in FIG. 5 . Source 54 includes a 5×6 array 68 of light generators, which includes a light generator 70 which is representative of all of the light generators in the array 68. Each of the light generators, including 70, produces a collimated beam of light directed perpendicular to the cassette 58 and covering an area. The light generator 70 is further shown in an elevation view in FIG. 6 . Light source 54 includes holes 71, 73, 75 and 77 for receiving the rods 30, 32, 34 and 36.

Collimated light sources are well known in the art. Multiple embodiments of collimated light source generators are usable with the present invention. Another collimated light generator is described in U.S. Pat. No. 7,758,208 issued Jul. 20, 2010 which patent is incorporated herein by reference in its entirety.

The light generator 70, which is shown in FIG. 5 within an array of such light generators, is further described in FIG. 6 . The light generator 70 includes a reflector 79 with an essentially parabolic shape and having an interior reflective surface 98. An LED 80 is mounted on a platform 81 at the focal point of the reflector 79. An electrical connector 82 is connected to the platform 81 and includes two conductive lines connected to provide electrical power to the LED 80. When power is applied to the LED 80, light is generated around the periphery of the LED and is directed toward the reflective surface 98. The angle of light generated by the LED 80 and the curvature of the surface 98 produce a collimated light beam 83. Such a collimated light source is shown in U.S. Pat. No. 7,112,916, which issued Sep. 26, 2006, and which patent is incorporated by reference herein in its entirety.

The cassette 58 is shown in an elevation section view in FIG. 7 . Cassette 58 comprises a top layer 136 and a bottom layer 138. After fabrication as separate layers, the layers 136 and 138 are bonded together to form the cassette 58. Both of these layers are made of a non-electrical-conducting material such as a polymer plastic.

The operational unit 10, shown in FIG. 1 , is further shown in FIG. 8 with additional operational components. On the interior of enclosure 11 there is the light source 54, cassette 58, imager and processor unit 60. Further included is a power supply 84 which receives power from line 16 and provides power via power cable 85 to the processor unit 60 and to the cassette 58. A temperature sensor 91 is mounted on the cassette 58 to measure the temperature of the cassette 58. The temperature sensor 91 is connected to the system controller 14 via a cable 94 to provide a temperature measurement of the cassette 58 to the controller 14. The thermal control unit 26 is coupled by a cable 28 to the controller 14. The controller 14 measures the temperature of the cassette 58 by the temperature sensor 91 and activates the thermal control unit 26 to provide wanner air or cooler air to within the enclosure 11 via a duct 27 to drive the temperature of the cassette to a selected temperature, for example, typical human body temperature.

The above embodiment in FIG. 8 has a power line that is directly connected to the cassette 58. An alternative configuration has a light power transmitter on the unit 60 for each chamber of the cassette 58. In this alternative configuration there is adjacent to each chamber of the cassette 58 a light power receiver that receives the light power beam from the underlying transmitter and converts the light power to electrical power that is provided to a chamber driver 318 shown in FIG. 21 . By use of the light power transmission, there is no requirement to have any power electrical connection to the cassette 58.

The cassette 58 has an array of holding chambers. One embodiment of the cassette 58 has an array of 30 holding chambers, as shown in FIG. 9 . The cassette 58, as shown in FIG. 9 for an embodiment of the invention, has 30 holding chambers 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240 and 242. The cassette 58 input manifold comprises distribution line 140 and chamber input lines 142, 144, 146, 148, 150 and 152. The output manifold comprises chamber output lines 158, 160, 162, 164, 166 and 170, the collection line 180 and the return line 182. This manifold configuration provides approximately the same blood flow path distance from the input of line 140 to the output of line 182 for the blood flowing through each of the holding chambers. The chambers and manifold lines are molded on the bottom side of the layer 136. This configuration contributes to a more uniform flow of blood through the holding chambers and more uniform fluid flow pressure gradient through the cassette 58.

Input line 142 supplies blood to each of the chambers 184, 186, 188, 190, 192. Each chamber can have, for example, an X dimension of 2 centimeters, a Y dimension of 2 centimeters, and a thickness (Z dimension) of 8 microns. The facing area of each chamber is therefore 4 square centimeters. The opening width from the input line 142 into chamber 184 is the same as the Y dimension of the chamber, in this example, 2 centimeters. Likewise, the output from each chamber, such as 184, is the Y dimension, in this example, 2 centimeters. A chamber, as viewed at the input, is relatively wide (2 centimeters) and relatively thin (8 microns). This configuration is the same for all of the remaining holding chambers in cassette 58. Each of the chambers has an input port and an output port. See FIG. 15 . Between the input line, such as 142, and the input port to a chamber, such as 184, there is a flow path having the same width and height as the chamber and a length of, for example, 0.1 to 0.4 centimeters. There is a similar flow path at the output port of each chamber. See FIG. 15 . These flow paths assist in providing a uniform fluid flow through the chamber. These flow paths are shown in FIG. 15 as flow path regions 251 and 253.

The blood leaves the holding chambers 184-242 and moves into the corresponding connected chamber output lines 158-168. The exit passageway from a chamber is the same configuration as the input passageway, that is, for this embodiment, the exit passageway is 2 centimeters wide and 8 microns thick. The blood flows through the output lines 158-168 into the collection line 180 and then into the return line 182.

As a flow example, referring to FIG. 9 , blood is driven into distribution line 140 and then into chamber input line 150 and at the far end of this line, into chamber 232. After the blood is analyzed, the blood in chamber 232 is driven out of the chamber by pump 62 into the chamber output line 166 and from the end of line 166 into the collection line 180. From line 180, the blood flows into the return line 182 and then into the blood return line 24. The blood travels through the cassette input manifold to all of the chambers and returns from all of the chambers through the cassette output manifold.

Further referring to FIG. 9 , the cassette 58 is provided with alignment holes 252, 254, 256 and 258. The cassette 58 is lowered onto the corresponding upward facing rods 30, 32, 34 and 36, see FIG. 2 , mounted inside the operational unit 10, which pass through corresponding aligned holes in the imager and processor unit 60. See FIG. 3 . The rods pass through the holes in the cassette 58 to provide alignment of the cassette 58 with the imager and processor unit 60. The light source 54 (FIG. 3 ) has corresponding alignment holes to receive the rods 30, 32, 34 and 36 so that the imager and processor unit 60, cassette 58, and light source 54 are aligned with each other. The top ends of the rods are threaded so that nuts 38, 40, 42 and 44 (See FIG. 2 ) can be applied to each rod and tightened so that all three of these units are compressed together and held in alignment with each other.

FIG. 9 shows a top, planar view of the top layer 136 of cassette 58. Each of the holding chambers 184-242 comprises a recessed region into the bottom side of the top layer 136. Each chamber recess, in one embodiment, is approximately 8 microns thick, 2 centimeters long and 2 centimeters wide. Referring to FIG. 10 , each holding chamber includes a plurality of long, thin ridges 248, illustrated as horizontal lines in each chamber in FIG. 9 , and shown in detail in FIG. 10 , which is a section view along line 10-10 of a representative holding chamber 196 in FIG. 9 . The ridges 248 are formed as a part of the upper layer 136. Example dimensions for a holding chamber and the ridges 248 are shown in FIG. The holding chamber 196 is approximately 2 centimeters wide, as shown, and 2 centimeters long, not shown. The ridges 248 extend for the length (2 centimeters) of the holding chamber 196. Each ridge, in an embodiment, is, for example, 8 microns high and 4 microns wide. In this embodiment, each of the holding chambers 184-242, has a thickness of 8 microns. In this example, there are 20 of the elongate ridges spaced in parallel across a distance of 2 centimeters. Therefore, the spacing between the ridges is approximately 950 microns. Each of the ridges 248 serves as a support for the bottom layer 138, see FIG. 7 , which is pressed against the top of the ridges 248 shown in FIG. 10 . The ridges 248 also function as spacers to maintain an essentially uniform 8 micron thickness over all of the area of each holding chamber. The ridges 248, in this configuration, further form 21 flow channels through the chamber. These channels reduce the lateral flow of blood in a chamber and support a more straight-through fluid flow from the input to the output of each chamber.

FIG. 11 is a section view taken along lines 11-11 in FIG. 9 in the distribution line 140. The distribution line flow channel has a flat-bottom with semi-circular cross section that has been pressed or molded into the top layer 136. The flat, and sealing, surface of the flow line 140 is provided by the top surface of the bottom layer 138. FIG. 12 is a section view take along lines 12-12 in FIG. 9 located in the input line 144. It is likewise pressed or molded into the top layer 136 and covered with the bottom layer 138. The cross-sectional area of line 144 at 12-12 is substantially smaller than that of line 140 at 11-11. There is a greater volume of blood flow through line 14 at 11-11 than through line 144 at 12-12.

All of the layers 136 and 138 are fabricated of, for example, transparent polycarbonate plastic, produced by a pressing or molding process such as described in U.S. Pat. No. 6,998,076 issued Feb. 14, 2006 which patent is incorporated herein by reference in its entirety. Alternative methods to the use of light for transmission of power are power transmission using electrostatic or magnetic technology. As an example embodiment, the top layer 136 can be approximately 2-3 millimeters thick, bottom layer 138 can be 1-1.5 millimeters thick for a total cassette 58 thickness of approximately 3-4.5 millimeters. Structure can be molded into both the top and bottom layers.

The top layer 136 of cassette 58 can be fabricated by the use of polycarbonate injection molding and a metal mold. An etched glass master is used to form the metal stamping mold. To make the glass master, the process starts with a sheet of glass. The sheet of glass, approximately 5 millimeters thick, is sequentially masked with photoresist patterns (as done in the manufacture of semiconductors) and an acid is applied to etch the non-masked portions. The acid removes a portion of the glass, producing a recessed pattern in the glass and forming the distribution lines and holding chambers. The final 8 micron etch can be done by plasma etching to produce more vertical sidewalls on the ridges 248. After removing the last photoresist, the surface of the glass mold is treated with a mold-release component, and then is covered with a layer of nickel or silver using an electrodeless plating method. Sputtering can be used, or a colloidal silver method can be used. Then, nickel is electroplated over the surface to a thickness of perhaps 0.5 cm forming a metal mold. After separating the electroformed nickel mold from the glass master, the metal mold has raised areas corresponding to the distribution lines and holding chambers. This process is similar to the manufacturing process for phonograph records, compact discs and DVDs as shown in U.S. Pat. No. 6,998,076 noted above. Heated polycarbonate injection molding is used with the metal mold to form the recessed flow channels and holding chambers in what will be the top layer of the cassette. The polycarbonate flows around the raised areas in the metal mold. When the metal mold and polycarbonate are cooled, the polycarbonate sheet is removed and it has the configuration for the top layer 136, as shown in FIGS. 9-12 . Structure can be molded into both the top and bottom layers.

Alternately, a metal mold can be machined or etched to have the configuration to produce the cassette top layer 136 by applying a sheet of polycarbonate to the mold, heating both the mold and the sheet and allowing the polycarbonate to flow into the metal mold to produce the desired shape for the cassette 58.

FIG. 13 is an illustration of the cassette 58 together with the peristaltic pump 62 and the blood flow lines. The blood input line 22 is positioned in the pump 62 between pump rollers 62 a and 62 b and a circular pump pressure plate 66. The rollers rotate about a center shaft and compress the line 22 against the interior curved surface of plate 66. The rollers apply sufficient force to close the flexible line 22 and, as they rotate, they force blood to flow through the line 22 toward the cassette 58. The pump 62 can be started and stopped as needed to pump blood to the cassette 58. After the blood has passed through the cassette 58, it flows through the return line 24 to the catheter 20 and then back to the patient 18. The structure and operation of a peristaltic pump is well known in the art, particularly in the field of kidney dialysis.

The flow of blood through the lines and chambers of the cassette 58 is shown in FIG. 14 . This is a top view of the layer 136. Blood enters the input line 22 into distribution line 140 and is sequentially distributed into the chamber input lines 142-152. Note that as the volume of blood flowing through line 140 is decreased, the size of the line 140 is correspondingly decreased. Note that each of the distribution lines 142-152 is tapered so the line size is decreased as the amount of blood flowing in the line decreases. For example, blood flowing in through input line 22 has a portion thereof directed into distribution line 142 and a portion of that flow enters holding chamber 186. As described previously, the chamber 186 is approximately 8 microns high and there are parallel ridges 248 that guide the blood in a uniform flow through the chamber 186. This substantially reduces transverse blood flow in a chamber. At the exit of chamber 186, the blood enters output line 158 where it joins the blood that has passed through chamber 184. The blood from the chambers 184 and 186 flows through output line 158 and is joined sequentially by the blood from chambers 188, 190 and 192. The blood that has flowed through the chambers 184-192 then enters the collection line 180. The blood from all of the holding chambers travels into the collection line 180 from which it flows into the cassette 58 return line 182 to the blood return line 24. Each chamber has an interior space between opposed walls.

Note in FIG. 14 that the configuration of flow lines and chambers provides approximate the same travel distance for blood flowing through each of the holding chambers 184-242. In each flow path, the blood flows through or beside 10 holding chambers. For example, the blood flow through chamber 206 first passes chambers 184, 194 and 204 then flows through chamber 206 and then passes chambers 208, 210, 212, 222, 232 and 242, for a total distance of 10 chambers. This configuration of chambers and flow lines contributes to uniformity of blood flow and uniformity of pressure gradient reduction for blood flow through the cassette 58.

Referring to FIG. 15 , there is shown a chamber 244, which is representative of the chambers 184-242 described above. This chamber 244 is in the bottom surface of the plastic body of the top layer 136 of the cassette 58. (See FIG. 7 ). The layer 136 has molded ridges 283 and 284, see FIG. 16 , which are shown as a group 248 in FIG. 10 . The chamber 244 is subdivided into an identification zone 246 and a processing zone 250. A region 271 of the processing zone 250 is shown in greater detail in FIG. 16 . A region 280 of processing zone 250 is shown in greater detail in FIG. 17 . An input port flow path region 251 transports blood into chamber 244 and an output port flow path region 253 receives blood from chamber 244.

As shown in FIG. 15 , in operation, blood flows through an input line into the identification zone 246 where it is stopped and an image of this zone is produced by a light source which illuminates the chamber and cell shadow images are detected by a light sensor array on the opposite side. The data from the sensor array is electronically processed using a reference library of pathogen cells images to locate pathogen cells in the chamber identification zone 246. After the pathogen cells have been located in the channels of the chamber 244, a travel time is taken from a reference database table to specify the travel time for each pathogen cell to the processing zone after the pump is started. The pump is started and when each travel time in each channel elapses, a voltage is applied to electrodes in the sides of the channel in the processing zone to apply electrical energy to the pathogen cell in the channel in the processing zone to neutralize the pathogen cell. The blood continues to flow through the processing zone until all of the identified pathogen cells have passed through the processing zone. The blood flow is then stopped and the process is repeated. Further structure of the processing zone is described below.

The region 271 of the processing zone 250 is shown in more detail in FIG. 16 . This view shows channels 272, 273 and 274. Channel 272 has electrical insulating layers 275 and 276 on opposite vertical walls of the channel 272. Channel 273 has similar insulating layers 277 and 278. Insulating layer 277 covers conducting layer 287. Similarly, channel 274 includes a single shown electrical insulating layer 279. The wall of the layer 136 adjacent channel 272 has a planar conductive layer 285 between the body of the layer 136 and the insulating layer 275. The ridge 283 has a conductive layer 286 between the body of the ridge and the insulating layer 276. The other side of ridge 283 has a similar configuration with a conductive layer 287 between the body of the ridge 283 and the insulating layer 277. Ridge 284 has a similar configuration with conductive layers 288 and 289. Channel 274 has a wall electrical insulating layer 290 over conductive layer 289.

Referring to FIG. 17 , the conductive layers on opposite interior surfaces of the channels, for example, layers 285 and 286 at channel 272, function as electrodes. When a voltage is applied between these electrodes, an electric field is established between the electrodes. This electric field has sufficient intensity to neutralize (kill) a pathogen cell which is in the channel between the electrodes. The insulating layers over the conductive layers prevent the flow of any electrical current between the electrodes.

In further reference to FIG. 17 , there is a conductive pad 292 on the base of the channel 272, the pad 292 being electrically connected to the conducting layer 285. A second pad 293 is electrically connected to conducting layer 286. An insulating layer 294 covers the pads 292 and 293 to insulate these pads from the blood in the channel 272. Channel 273 includes conductive pads 295 and 296 electrically connected to respective conductive layers 287 and 288. Pads 295 and 296 are covered by an electrical insulating layer 297. Likewise, in channel 274, pads 298 and 299 are connected electrically respectively to conducting layers 289 and 290. Pads 298 and 299 are covered by electrical insulating layer 305. Conductive layer 290 is covered by insulating layer 307. The conductors, such as 285 and 289, have a length along the corresponding channel 272, in the range of, for example, 10-200 microns.

When a voltage differential is applied between the pads 292 and 293, an electric field is established between the conductive layers 285 and 286 which are on opposite sides of the channel 272. Electrical fields are similarly established in channels 273 and 274 when an electrical voltage differential is applied to pads 295 and 296 and to pads 298 and 299. Each channel of each chamber has a similar conductive layer (electrode) configuration.

Referring to FIG. 18 , there is shown a section view of a chamber with ridges, see FIGS. 16 and 17 , illustrating the components that provide electrical connections from an electrical driver unit to the pads in the channels. Two pads are described in detail and represent the configuration for the conductors for all of the pads. Pad 292 is electrically connected to a through-hole conductor 309 to a surface pad 311. A second through hole conductor and second surface pad (not shown) are electrically connected to the pad 293, and are located behind the conductor 309 and pad 311. Another example is a through-hole conductor 313 connected electrically to pad 295 and a surface pad 315. Behind, in FIG. 18 , the conductor 313 and pad 315 is a corresponding conductor and pad for pad 296, see FIG. 17 . There are two through-hole conductors and corresponding surface pads for each of the channels. Pads 311 and 315 are included in a set of surface pads 317.

Further referring to FIG. 18 , there is a chamber driver 318, a packaged electronic integrated circuit, which has a set of hemispherical pads 320 including pads 322 and 324 which respectively align and are placed in physical contact with pads 311 and 315. The pads in set 320 physically align with and are set to be in electrical contact with the respective pads in set 317. Driver 318 further includes a light receiver 348 and power connection pads 349 and 350, which receive electrical power for operating the driver 318. The light receiver 348 receives timing data for operating the driver 318 for selectively applying voltages to the pairs of electrical layers in each of the channels.

FIG. 19 shows a group of the pads in set 320 including the pads 322 and 324. FIG. 20 illustrates a group of the pads in set 317 including pads 311 and 315. Pads in set 317 are fabricated on the top surface of the layer 136. Pads in set 320 are fabricated on the bottom surface of the driver 318. Driver 318 is mounted on the top of layer 136 so that the pads on the driver in set 320 match up one-to-one with the pads in set 317.

An electrical block diagram of the driver 318 is shown in FIG. 21 . Driver 318 is preferably a packaged integrated circuit. The driver 318 includes the light receiver 348 which receives pulsed light from an associated processor, described below, with data defining the amplitude and voltages to be applied to the electrodes (conducting layers) in each of the channels in the associated chamber. The light receiver 348 provides a received signal via a line 351 to a data receiver 352. The data receiver 352 provides a digital data stream via a line 353 to a processor 354. The processor 354 is coupled via a bus 355 to a multiplexor/driver 356. Driver 356 is electrically connected to the pads in the set 320. Power pads 349 and 350 are connected to a power receiver and power driver 357. Pads 349 and 350 are connected to the power supply 84 (See FIG. 8 ). The power receiver and power driver 357 provides electrical power to the data receiver 352 via a line 359, to the light receiver 348 via a line 361, to the processor 354 via a line 363 and to the multiplexor/driver 356 via a line 365.

An alternate configuration to that shown in FIGS. 16 and 17 is shown in FIGS. 22 and 23 . The structure shown in FIGS. 22 and 23 is the same as that in FIGS. 16 and 17 with the exception that the insulating layers are not present over the conductive layers that are on the opposing walls of each channel. The absence of the insulating layers places the conductive layers, such as 285 and 286 which are on opposite sides of channel 272, in electrical contact with the fluid in channel 272. This creates a flow of electrical current through the blood fluid. Blood is electrically conductive and has resistivity.

FIG. 24 is an electrical block diagram of the system shown in FIG. 1 with detailed structure shown for the imager and processor unit 60. The unit 60, in one embodiment, includes a printed circuit board with components mounted on it. The system controller 14 (See FIG. 1 ) is coupled via a cable 12 to the unit 60 by use of a connector 391 and a cable 392 to a master controller 434. The controller 434 can be, for example, a microprocessor, a dedicated gate array or other processing device. The controller 434 can activate and deactivate the light source 54 and pump 62 via the cable 12. The master controller 434 is connected via a cable 393 to an input/output (I/O) multiplexor 394. The multiplexor 394 is connected to each of a plurality of assemblies 395. In an embodiment, there is one of the assemblies 395 for each of the chambers of the cassette 58, such as the 30 chambers 184-242 shown in FIG. 9 . The master controller 434 can communicate via the multiplexor 394 to each of the assemblies 395 and can receive communication from each of the assemblies 395. Each assembly 395 includes a light sensor 260 which is positioned below and aligned with a corresponding chamber in the group of chambers 184-242. Each light sensor 260 is a light sensor array of pixels. See FIG. 25 . The multiplexor 394 communicates with the assembly 395 via cables 396, 397 and 398. There is a similar set of cables, such as printed circuit board traces, for each of the other assemblies in the unit 60.

Further in reference to FIG. 24 , each assembly 395 includes a memory 399 which receives from the light sensor 260 digital data via a cable 400 comprising data and control lines (See FIG. 25 ). When the light sensor 260 has received light and has a data state for each pixel therein, this data can be transferred to the associated memory 399. Each assembly 395 further includes a chamber processor 401 which has a data bus 403 and control line 407 coupled to the memory 399. The processor 401 can command that part or all of the data in memory 399 be transferred to the processor 401 to be processed. The master controller 434 communicates via the multiplexor 294 via cable 396 to the chamber processor 401, the cable 397 to the light sensor 260 and cable 398 to the memory 399. Each assembly 395 further includes a light data transmitter 409, for example a modulated laser beam generator, connected via a data transmission and control cable 411. The light data transmitter 409 sends data and control commands to a corresponding chamber driver 318. See FIG. 21 .

An example light sensor array integrated circuit for use with the present invention is shown in FIG. 25 . A sensor array 260 includes an array 262 of individual pixel cells, each pixel further described below. Surrounding the array 262 of pixel cells is circuitry termed control and I/O (Input and/or Output) 264 which controls the operation of the sensor array 260 and the transfer of pixel data collected by the sensor array 260. A group of data lines 266, for example 16 parallel lines, transfers pixel data from the pixel array 262 to an associated memory. A set of control and power lines 268, for example 8 lines, controls the operation of the sensor array 260 and provides power for operation of the sensor array 260 circuitry. As further described below, the sensor array receives a reset signal to set an initial charge state in each of the pixels. When the pixels are exposed to light, each pixel is discharged from the initial state to a final state (the pixel data) depending on the amount of light that was received by the pixel. A command is sent through lines 268 which causes the sensor array 260 to transfer the collected pixel data through one or more of the lines 266 to an associated memory.

As an example, the pixel array 262 can have a pixel size of 0.50 micron by 0.50 micron (square configuration) and the light sensitive array has a size of 2 centimeters by 2 centimeters. If there is only one bit per pixel, either light or dark, the pixel data for one image is the size of the number of pixels. These dimensions are exemplary only, and a sensor array larger or smaller than array 262, as presented, may be used.

A partial section, top view of the pixel array 262 is shown in FIG. 25 . This illustration, for a design having the dimensions listed above, of a pixel array includes a dimension scale in microns. This top left corner of the array 262 shows individual pixels, each a square having side dimensions of 0.5 micron. A single pixel, such as 270 is representative of all of the pixels in the array 262.

A circuit for each of the pixels, such as 270, in the array 260, can be any one of many types. A 3-T (three transistor) pixel circuit is shown in FIG. 26 and a 4-T (four transistor) pixel circuit is shown in FIG. 27 .

Referring to FIG. 26 , a 3-T pixel circuit 300 includes a photodiode (PD) 302, a transfer transistor 306, a reset transistor 304, a drive transistor 308 and a floating diffusion (FD) 310. A reset signal (RS) is sent through a line 314 to the gate of reset transistor 304. A transfer control signal (TG) is provided through a line 316 to the gate of transistor 306. The image data produced by pixel circuit 300 is transmitted through column line 312.

In operation, the pixel circuit 300 is initially reset by turning transistor 304 (RX) on to charge node FD 310 to VDD. Next the TG signal turns on TX transistor 306 which couples the node FD to the cathode of photodiode 302. Upon receiving light at the photodiode 302, the diode reverse conducts and discharges node FD dependent upon the amount of light received by the diode. The charge on node FD drives the transistor 308 (DX) which applies a corresponding current to the column line 302.

A 4-T pixel circuit 326 is shown in FIG. 27 . This circuit has a photodiode (PD) 328, a reset transistor 330 (RX), a transfer transistor 332 (TX), a drive transistor 334 (DX), and a select transistor 336 (SX). A floating diffusion 338 (FD) is connected to the gate of transistor 334. Transistor 330 (RX) receives a reset signal through line 342. Transistor 332 (TX) receives a drive signal (TG) through a line 344. Transistor 336 (SX) receives at its gate a select control signal (SEL) via a line 346.

The pixel data, which is the measured light, is sent through the column lines 312 and 340 in FIGS. 26 and 27 . At the end of these lines there is an analog to digital converter to produce a high or low, 1 or 0, digital signal. This is essentially a threshold detection. Each pixel data represents dark or light, depending on how much light was received at the pixel.

Operation of the pixel circuit 326 (FIG. 27 ) begins with receipt of a reset (RS) signal at transistor 330 to charge node FD 338 to VDD. Next, the transfer control signal (TG) turns on transistor 332 to couple the cathode of photodiode 328 to node FD. When the photodiode 328 receives light, charge is drawn from node FD to reduce the voltage on node FD, which drives the gate of transistor 334 (DX). For readout of data from the pixel, signal SEL is applied to turn on transistor 336 (SX) to couple transistor 334 (DX) to the column line 340. The column line 340 is sequentially used to transfer data from all of the pixels connected to the column line.

FIGS. 28 and 29 illustrate a physical integrated circuit structure for implementing the 4-T pixel shown in FIG. 27 . Layout 358 in FIG. 28 is a top view. A unit pixel area 362 is the area occupied by the pixel structure. A deep trench isolation (DTI) region 364 serves to isolate each pixel from surrounding pixels. Active area 366 is the area of the pixel which receives light. A shallow trench isolation (STI) 368 separates active elements of the pixel. First border 370, second border 378 and third border 380 serve to isolate elements of the pixel circuit to reduce noise. 372 is a ground element. 374 is a transfer gate. 376 is a floating diffusion. 382 is a p-well. 384 is a p-well. 386 is the drive transistor gate. 388 is the select transistor gate and 390 is the reset transistor gate.

FIG. 29 is a section view layout 402 along line 29-29 of the structure shown in FIG. 28 . The common elements in FIGS. 39 and 401 have the same reference numerals. Element 404 is an oxide isolating layer, 405 is a border, 406 is a polysilicon isolation layer and 410 is a photodiode in conjunction with the epitaxial layer 412. Element 414 is an anti-reflection layer. 420 is a gate isolation layer. 424 is a floating diffusion (FD 338 in FIG. 27 ). Light, shown by the upward pointing vertical arrows in FIG. 29 , produced by the light source 54 in FIG. 3 , is transmitted to the pixel structure and in particular to the photodiode for measuring the light received by this one pixel.

Referring to FIGS. 30, 31 and 32 , there is shown a physical calibration for the alignment of a cassette chamber with the underlying light sensor. A segment 416 of a chamber, such as any of chambers 184-242 (FIG. 9 ) is subdivided into a set of areas, which, in this example, each area has a size of 100 microns by 100 microns. Area 418 is near the corner of a cassette chamber, and FIG. 31 illustrates a middle region of the area 418. A light blocking calibration marker 419 is positioned approximately in the middle of area 418. The upper left corner of the marker 419 is at the position of 150 microns horizontal and 150 microns vertical. The marker 419 is printed on the interior surface of the cassette chamber. The marker, in this example, has a unique L-shape—it is 2 microns long, 1 micron wide and the body is ½ micron wide. This shape can be readily identified in pattern recognition. FIG. 32 illustrates a region of the light sensor beneath the chamber having the marker. If the chamber and underlying light sensor were perfectly aligned, the shadow image of the chamber marker 419 would be at the same position in the light sensor, as shown by the dotted marker outline 421. But, if the chamber and light sensor are not in perfect alignment, the marker 419 could produce a shadow image 423 which is offset from the dotted marker outline 421. In the illustrated example, the shadow image 423 is offset by 6 microns to the right and 8 microns down. Thus, for the area 418, the alignment correction is (−6, −8). Thus, for any image in the 418 area for the light sensor, the position determined in the light sensor is adjusted by −6 microns horizontally and −8 microns vertically. Each of the areas of the cassette chamber is provided with a printed marker, such as 419 and the shadow image of each marker in the light sensor is determined. A physical calibration table is prepared having the correction numbers for each area of the cassette chamber.

Referring to FIGS. 25 and 31-32 , the sensor array can be divided into calibrations zones. For a 2 cm by 2 cm sensor array, each calibration zone can be, for example, 100 microns by 100 microns. With these sizes, the array 262 has 4×10⁴ calibration zones. If the calibration zone is larger, there will be fewer calibration zones in the sensor array. Each calibration zone can be calibrated, as described, and the calibration values can be different between calibration zones. This will compensate for nonlinearities across the sensor array 262.

In a summary of system operation, the controller 434 drives the pump 62 to fill the holding chambers in a cassette 58 (See FIGS. 3, 14 and 124 ) with blood. When the holding chambers are filled, the pump is stopped. The controller then sends a reset command to each sensor array to reset all of the pixels in each array. Next, the controller sends an activation command to all pixels in all sensor arrays. After this, the controller 434 activates the light generator 54 to produce visible light for a set period of time. When this time has elapsed, the controller 434 sends a control signal to all pixels in all sensor arrays to end activation. Next, the controller 434 sends a command to each sensor array 260 to download the collected pixel data to the corresponding memory 399. After the pixel data has been loaded in the memories, the controller 434 commands each of the chamber processors mounted on board 432 to process the pixel data in the corresponding sensor array for pattern recognition using an image library to identify and locate the imaged pathogen cells. Each processor determines, after applying location correction factors if required, the location in the chamber for each identified pathogen cell image. The chamber processors send to the corresponding chamber drivers the location of each identified pathogen cell. The driver has a travel time table with values for each zone of each channel in the chamber. The controller 434 starts the pump 62 and sends a start command to all of the chamber processors which then send a start command to the chamber drivers which generate a drive voltage signal to the opposing conductors in each channel when each travel time expires for a detected pathogen cell thereby applying electrical energy (field or current) to the specific located pathogen cell. When the travel times have been completed, the controller 434 stops the pump 62 and the process of identification, fluid flow and generation of voltage signals is repeated.

The chamber processors described herein, one used with each sensor array, can be, for example, a microcomputer, a graphic processor or a custom gate array. The master controller can be, for example, a microcomputer or a custom gate array.

The 30 sensor arrays (See FIGS. 9 and 24 ) each align with a holding chamber in cassette 58. There is a one-to-one relationship. For example, holding chamber 184 (FIG. 9 ) is positioned over and aligned with a light sensor such as 260 (FIG. 24 ). Each of the remaining holding chambers (FIG. 9 ) of the cassette 58 is likewise located over and aligned with a sensor array (See FIG. 24 )

Operation of the apparatus described herein can include an initial calibration of the light energy produced from the light source 54 to be sufficient to activate the individual pixels in the light sensors 260 shown in FIG. 24 . Also referring to FIG. 3 , as directed by the master controller 434 after receiving an energy calibration command from the system controller 14, the energy calibration process first resets all of the pixels in all of the sensor arrays 260. Next, it activates all of the pixels in all of the sensor arrays and then activates the light generation from the light generator 54 for a selected time. The pixels in the light sensors are then deactivated, the pixel data transferred to the corresponding memory and the processor activated to run a light energy calibration routine. If the light energy is sufficient, all of the pixels will be light, that is, no dark pixels since there is nothing in the cassette holding chambers during this calibration process. The markers in the chambers are excluded. The processor counts the number of dark pixels. The master controller polls all of the chamber processors to collect the number of dark pixels. If the number of dark pixels exceeds a preset threshold, such as 0.001%, the calibration process is repeated and the selected time is incrementally increased until the number of dark pixels is less than the preset threshold. If the initial measurement shows the number of dark pixels to be less than the present threshold, the process is repeated with shorter light activation times until the threshold is crossed and the last lower value is selected as the light activation time. The light energy can be varied by changing the length of time the light is on, or by varying the intensity of the light. In either case, a light activation value, either time or intensity, will be produced.

Light energy calibration can also be performed after the blood holding chambers have been filled as shown by the steps in FIGS. 33A and 33B. The system controller initiates the filled chambers light energy calibration process by sending a command to the master controller 434. See step 568. Referring to FIG. 24 , the controller 434 drives the pump 62 to fill the holding chambers in cassette 58 (FIGS. 3 and 9 ). See step 570. Next, in step 572, the controller 434 sends a reset command to each of the light sensors 260. After the pixels in each sensor are reset, the controller 434 commands (step 573) each light sensor array to be activated. Next, in step 574 the light generator 54 is activated for a period of time X. The controller 434, in step 575, deactivates all of the light sensor arrays, and in step 576 commands each sensor array to download its pixel data to the corresponding memory. Next, in step 577, the controller commands each chamber processor associated with a sensor array to (step 578) access the pixel data in the corresponding memory and perform a light calibration process in which the number of light transitions between adjacent pixels is counted. The transition can be either light to dark or dark to light. Each pixel has four adjacent pixels and each possible transition is examined. For example, a dark pixel surrounded by four light pixels produces four transitions. In step 588, the controller 434 then collects the pixel transition count from each processor and adds them together to produce a total transition count corresponding to the period of time the light generator was on. In step 589, the master controller produces a table of light durations as shown below in Table 1. Next the above process is repeated with an incrementally longer period of time for the operation of the light generator. The number of transitions for this period is determined and recorded. Next, in question step 590, it is determined if the peak value of the number of light transitions has been passed. This is selected, for example, by having 100 sequential transition counts lower than a preceding transition count. If the response to question step 590 is “NO”, in step 592, the value of X is increased by a selected increment, and control is returned to step 571. This process is repeated until a peak of transition number is reached, as noted. If the response to question step 590 is “YES”, the master controller 434, in step 594 sends the completed table of light duration and count of pixel transitions to the system controller 14. This calibration process terminates at STOP step 596. An example of such data is as follows. The light energy value is a relative measure and the Pixel Transitions number is a truncated value, such as billions of transitions.

TABLE 1 Relative Light Energy Pixel Transitions 1 50 2 65 3 85 4 100 5 120 6 140 7 150 8 165 9 160 10 150 11 135 12 125 13 115 14 105 15 90 As seen in the above data listing, the optimum light energy value is “8” which corresponds to the pixel transition value “165”. The number of pixel transitions is an indicator of the quantity of image information present in the pixel data and is likely the best image data. Therefore, for this instance of testing, the light energy should be set to the relative level of “8” for the process described herein to identify and locate pathogen cells in the blood. As noted above, the light energy can be varied by time duration or by the intensity of the light produced.

A pathogen cell, together with a measurement scale, is shown in multiple positions in FIG. 34 . E. coli is a rod-shaped bacterium. The dimensions for this bacterium can vary but some species can be in the range of 2-3 microns long and 0.25 to 1 micron thick. In FIG. 34 , there is shown in the left column an e. coli bacteria cell 600. The left column shows an actual view of a cell and the two right columns show shadow images that can be produced by that view of the cell by the sensor arrays (FIG. 25 ). These views are based on a system as described with 0.50 micron by 0.50 micron sensor array pixels. The right two columns show shadow images produced by the corresponding cell in the left column. The cell 600 is shown at multiple rotations along a vertical axis with angles of 0, 15, 30, 45, 75 and 90 degrees. These multiple views are required because the cell could be at any rotation position as it is viewed in a holding chamber. The right two columns (a) and (b) represent possible variations on the image produced by the cell positioned at the indicated rotation. Images 602 and 604 can be produced by cell 600 at rotation of 0 degrees. These can differ due to edge effects and small threshold differences in pixel sensors. Images 606 and 608 could be produced for rotation 15 degrees, 610 and 612 for rotation 30 degrees, 614 and 616 for 45 degrees, 618 and 620 for 60 degrees, 622 and 624 for 75 degrees and 626 and 628 for 90 degrees. The images 602-628 are the image library for the pathogen cell 600. These images are the search targets in the pixel data for identifying and locating the pathogen cells. These images can be located in the pixel data by the use of pattern recognition. Pattern recognition for detecting predetermined images in a digital data field is well-known technology. An example patent describing such technology is U.S. Pat. No. 9,141,885 issued Sep. 22, 2015 which patent is incorporated herein by reference in its entirety.

Referring to FIG. 35 , there are shown views of corresponding shadow images of red blood cells, which comprise the majority of cells in human blood. The size of red blood cells can vary, but can be in the range of 6-8 microns. In FIG. 35 , left column, there is shown a red blood cell 638. A red blood cell has a disc shape with a flattened center where the thickness may be 1-2 microns. Cell 638 with a rotation of 0 degrees can produce the shadow image 638, with rotation degrees the shadow image 640 and with rotation of 90 degrees the shadow image 642. These images are included in the image library as being images to be ignored since they are different from the bacteria or other pathogen images that are sought to be found.

FIG. 36 shows a white blood cell 648 having a relatively large size and a white blood cell 650 having a smaller size. These cells are essentially spherical so appear approximately the same at all rotation angles. Cell 642 can produce a shadow image 652 and cell 650 can produce a shadow image 654. Again, these images 652 and 654 can be included in the cell library as images to ignore.

A blood platelet cell 660 is shown in FIG. 37 . A platelet is a biconvex discoid (lens-shaped) structure, 2-3 micron in greatest diameter. This shape is thin at the edge and thickest in the center. At a rotation of 0 degrees, the cell 660 can produce a shadow image 662, at a rotation of 45 degrees a shadow image 664 and at 90 degrees, a shadow image 666. As with the other normal blood cells, these images are used as recognition of cells to ignore in the processing operation.

Each of the cells in FIGS. 35, 36 and 37 are shown, for illustration, at a limited number of rotation angles; but the library can contain images representing a finer degree of rotation, for example, every 5 degrees of rotation.

The operation of the present disclosure in summary includes initially determining the static position of each pathogen in a channel in the cassette chamber. Next, the pump and a travel time timer are started simultaneously. The pump operation causes the pathogen cell to move from the initial location toward the processing zone of the chamber. When the travel time expires, the pathogen is located in the destruction region of the processing zone, the region having electrodes of opposite sides of the channel. When the travel time expires, the chamber driver generates a voltage waveform that is applied to the opposing electrodes in the processing zone and this action applies electrical energy to the pathogen cell. The applied electrical energy is sufficiently great to neutralize the pathogen cell located between the electrodes. The electrical energy can be applied as a field or current. One method of determining the travel time between the identification zone and the processing zone is described in reference to FIGS. 38 and 39 and the logical flow diagram for this process is shown in FIG. 40 .

Referring to FIGS. 38 and 39 , there is shown a representative channel 426, corresponding to each of the channels shown in the chamber in FIG. 15 . The channel 426 is divided into a plurality of sequential and contiguous channel zones, including exemplary channel zones 427, 428, 429 and 431. As an example, the channel 426 can be 8 microns wide and each zone is 6 microns long. The channel zones do not have any physical structure marking the position of each zone, but are defined by longitudinal position. If, for example, a channel is 2 centimeters long, it will have approximately 3333 channel zones. The channel 426 further includes arbitrarily defined sets of channel zones identified as a first window 433 of zones and a second window 435 of zones. An approximation of the flow rate of blood through the channels in the chambers of the cassette 58 can be calculated using the flow rate of the pump 62 and the geometry of the flow lines and chambers of the cassette 58. The channel zone 427 is selected to be near the input of the chamber. The location of the first window 433 is determined by use of the calculated approximate fluid flow rate of blood in a chamber and is sufficiently wide to accommodate the possible error in that flow rate. The second window 435 is set at a predetermined distance from the first window 433. A processing zone in channel 426 corresponds to the processing zone 250 in FIG. 15 . The opposed electrodes, see FIG. 16 on the sides of the channel define the processing zone and the length of this zone should be relatively short to have shorter electrodes and therefore more concentrated electrical energy applied to the fluid in the channel. The flow rate calibration process described in FIGS. 38 and 39 can more accurately establish the total travel time from each of the channel zones, where a pathogen cell is initially located, to the processing zone as compared to a flow rate determined by only pump rate, tubing and cassette geometry.

Referring to FIG. 39 , there is shown a chart of flow rate of fluid versus time. The pump starts at time t₁ where the fluid velocity is zero. After the pump starts, the fluid velocity increases until it reaches a constant velocity. This is shown as v₁. Depending on physical configuration, the time to reach constant velocity could be, for example, approximately 0.01 to 0.02 seconds. A time T1 is selected which is larger than the time for the fluid to reach constant velocity. A time T2 is selected which, when added to time T1, is the approximate travel time from the zone 427 to the second window 435. The total travel time, from zone 427, to the center of the processing zone 437 is TTi, the “i” representing each zone.

The calibration process, shown in FIGS. 38 and 39 , is described in detail in the logic diagram in FIG. 40 . In summary, the process begins with pumping fluid into the chambers of a cassette and then stopping the pump. The light sensor below a chamber is activated and the light source is turned on the illuminate the chambers. Pathogen cells in the channels of the chamber create shadow images in the pixels of the light sensor. The data from the light sensor is stored in a corresponding memory. See. FIG. 24 . The data is evaluated by a corresponding processor using pattern recognition to identify and locate pathogen cells, such as cell 439 in channel zone 427. The pump is activated and when the cell 439 is in the first window 433, the light sensor is reset and the light source is activated for a short flash, for example a millisecond or less, and the shadow image is created in the corresponding light sensor. The pixel data is processed by the corresponding chamber to identify and locate the cell 439, which as shown, is located in channel zone 429. The locations of zones 427 and 429 define the distance D1. The fluid is moving at the constant velocity when the cell is imaged at zone 429, but the light flash is of sufficiently short duration, as compared to the flow rate, that there is a clear image of the cell. This is essentially a “stop image” shot. The fluid continues to move until the pathogen cell is in the second window 435 where another flash shot image is taken as just described. The cell 429 is then determined to be in channel zone 431.

Further referring to FIGS. 38 and 39 , the distance between zones 429 and 431 are predetermined parameters. T1 and T2 and distance Dt (for each channel zone) are predetermined. T1 is selected to be less than the smallest total travel time. T3 is the flow time from the end of time T1 to the cell 439 arrival at the center of processing zone 437. D3 is the distance from zone 429 to the center of zone 437. The total travel time from a channel zone to the center of the processing zone is TTi. The constant velocity fluid flow rate (Vcv) between zones 429 and 431 is determined by the equation: Vcv=D2/T2. Therefore, the total travel time (TTi) from any channel zone to the center of the processing zone 437 is: TTi=T1+T3; T3=D3/Vcv, and therefore:

TTi=T1+(Dt−D1)(T2/D2).

Thus, after the calibration process described above has been performed for a channel in a chamber, the total travel time TTi can be calculated for each channel zone (i) in the identification field of the chamber. The term Dt is different for each channel zone in a single channel. Further, the same calibration process is performed for all of the channels in all of the chambers. A calibration table is prepared for each chamber that provides the travel time from each channel zone to the center of the corresponding processing zone. In operation, after a pathogen cell is identified in the detection zone and located in a specific channel zone, the pump is started and the pathogen cell moves toward the processing zone and when the total travel time, for that specific channel zone, expires, the pathogen cell is located in the processing zone. At that time, a voltage is applied to the electrodes in the processing zone to neutralize the pathogen cell as it passes through the processing zone. In this process, the fluid flow is continuous after the pathogen cell has been initially identified and located. After the blood in the chamber has been replaced, the pump is stopped and the process is repeated.

A logic flow description of the calibration process is shown in FIGS. 40A, 40B and 40C. The calibration process is begun at step 446 at the system controller 14. The calibration parameters and data are the pump drive time to fill the chambers, for example 15 seconds, first and second light source activation times LSRC1 and LSRC2. Values of these times can be, for example, respectively 1 second and 1-5 milliseconds. The cell library is the collection of pathogen images described above. The estimated travel times can be, for example T1=1-2 seconds and T2=4-10 seconds. The start calibration command and the calibration parameters are downloaded to the master controller 434 from the system controller 14 in step 448.

Continuing reference to FIG. 40A, in step 450, the master controller 434 starts the pump 62, runs the pump for the fill time and then stops the pump. Next, in step 452, the master controller 434 resets all of the light sensors so that they are prepared to receive light from the light source 54. In step 454, after the light sensors are reset, the master controller 434 activates the light source 54 for the time period LSRC1 and the light sensors receive light after it has passed through the chambers and shadow images of cells in the chambers are created in the pixel data in the light sensors. In step 456, after expiration of the time period LSRC1, the master controller 434 transfers the image data from the light sensors to the corresponding memories. See FIG. 24 . In step 457, the chamber processor, for each chamber, processes the image data by performing pattern recognition with the cell library to identify pathogen cells in the channel zones. In step 458, the chamber processor selects one located pathogen cell for the calibration process. The specific location zone for this selected cell is identified.

In step 460, the master controller 434 resets all of the light sensors. See zone 427 in FIG. 38 . Next, in step 462, the master controller concurrently starts the pump 62 and a calibration timer to run sequential times T1 and T2. At step 463, upon expiration of time T1, the light source 54 is activated for time period LSRC2. This takes a “stop action” image of cells in the channels in the first window 433. The fluid flow rate is slow in comparison to the on time of the light source so that a clear image is produced without stopping the fluid flow. At step 464, after the time LSRC2 has ended, the master controller 434 transfers the pixel data from each light sensor to the corresponding memory. In step 465, the chamber processors process the image data in the corresponding memories using the cell library and pattern recognition to identify and locate the cell previously identified in the channel at the initial channel zone. In step 466, the chamber processor determines the distance D1 which is between the initial channel zone location and the identified location in the first window 433.

In step 467, the master controller 434 resets all of the light sensors. Next, in step 468, when the time period TG2 expires, the master controller activates the light source 54 for the time duration LSRC2. In step 469, when the time period TG2 has expired, the master controller transfers the collected pixel data from each light sensor to the corresponding memory. In step 470, the chamber processors perform pattern recognition on the pixel data for pattern recognition and using the cell library as reference data, to locate the previously identified pathogen cell previously identified in the first window. Next, in step 471 the chamber processor determines the distance D2 which is the distance between the identified cell locations in the first and second windows. In step 472, the master controller 434 stops the pump.

In the next step 473, the chamber processor calculates the fluid velocity between the two locations in the windows, using distance D2 and time T2. See FIG. 38 . With this data the chamber processer determines the total travel time TTi for each channel zone (i) to the center of the processing zone. The travel times are determined for all channels in each chamber. In step 474, the chamber processors transfer the total travel time table of values for each chamber to the master controller 434. In step 476, the master controller transfers all of the travel time tables for all of the chambers to the system controller 14 and reports completion of the calibration process. In step 478, the system controller 14 displays an end of calibration report on its display screen and ends the calibration process.

By closely calibrating the travel time of each initially detected pathogen cell to the center of the processing, the length of the processing zone can be limited so that the maximum electrical energy can be applied to the pathogen cell in the processing zone and less blood fluid is exposed to the electrical energy. If the predicted total travel time number were to be less accurate, the electrodes in the processing zone would need to be longer to assure that the pathogen cell is in the processing zone when the electrical energy is applied.

An operation process for an embodiment of the present invention is shown in the logic flow in FIGS. 41A, 41B and 41C. This process utilizes the apparatus shown and described in the prior text and figures. The process begins with a start command, for example from an operator, at the system controller 14 in step 480. The system controller 14 downloads data and processing parameters, step 482, and a start command is sent to the master controller 434. The processing data and parameters include:

-   -   1. Pathogen image cell library.     -   2. Initial pump flow time and pump cycle on and off times. This         can be, for an example, an initial flow time of 20 seconds to         completely fill all of the chambers. After the start, a flow and         processing time of 10 seconds with a stop time of 2 seconds for         initial identification of pathogen cells. The 2 second stop with         10 second flow is repeated until the processing is completed.     -   3. A light generation time, for example, in a range of 20 to 100         milliseconds.     -   4. A light sensor collection time of, for example, within a         range of 5 to 50 milliseconds.     -   5. Voltage waveforms for application to the processing zone         electrodes     -   6. Alignment data for each sensor array.     -   7. Travel Time Table for each channel of each chamber.     -   8. Total processing time, for example, in the range of 6-24         hours.

In step 484, the master controller 434 sends certain data and processing parameters to the chamber processors. This includes the pathogen image library, the voltage waveforms for the channel electrodes in the processing zone, the alignment data for sensor arrays and the total travel time tables for each chamber. In step 486 the voltage waveforms and travel time tables are transferred from the chamber processors to the chamber drivers for each chamber.

In step 488, the master controller 434 runs the pump for the initial pump flow time to fill the chambers and then stops the pump. The master controller 434 also starts a total processing time timer. In step 490, the master controller resets all of the light sensor arrays so they are prepared to receive light. In step 492, the master controller 434 activates the light source 54 for the light generation time. Next, in step 494, the light sensors are activated to collect light for the pixel light collection time. In step 496 the collected pixel light data is transferred from the sensor arrays to a corresponding memory. In step 498, the master controller 434 commands each chamber processor to perform pattern recognition on the stored pixel data using the pathogen cell library and to locate each identified pathogen cell. In step 500, each chamber processor performs the pattern recognition and generates a listing of the pathogen cell locations in each channel of the corresponding chamber. Each identified pathogen cell is in a channel zone, see FIG. 38 , for example zone 428. The chamber processor also adjusts for any misalignment between cassette and sensor array with the alignment data. In step 502 each chamber processor, by use of the downloaded travel time table, determines the total travel time for each identified pathogen cell from its identified channel zone location to the center of the processing zone.

Further referring to FIG. 41B, in step 504 the determined travel times for each identified pathogen cell and the corresponding channel is transferred to the corresponding chamber drivers. This data transfer is done via the optical link from the chamber processor to the chamber driver, see FIG. 24 , light transmitter 409 and FIG. 21 , light receiver 348. In step 506 in FIG. 41C, the master controller 434 receives the data transfer completion reports for all chamber processors and then activates the pump 62 and sends chamber driver activation commands to all of the chamber processors. In step 508, the chamber processors send activation commands to the corresponding chamber drivers. In step 510, in response to the activation command, each chamber driver starts the timing for the total travel times for the identified pathogen cells in each channel. When a total travel time is completed for a channel, the corresponding chamber driver generates voltage waveforms which are applied separately to the electrodes in that channel in the processing zone, for example, electrodes 285 and 286 shown in FIG. 16 . In FIG. 42 there are shown waveforms 512 and 513. These waveforms are shown as a function of time “t” along the horizontal scale. The peak positive value is +V and the peak negative value is −V. When the total travel time has expired for a channel, the driver 318 (FIG. 18 ) applies waveform 512 to one electrode, such as 285 and applies the second waveform 513 to the other electrode 286. Because these waveforms are inverses, the voltage difference between the electrodes is 2V.

Referring to FIGS. 16 and 42 , if the value of V is, for example, 10 volts, the voltage difference of 20 volts is applied between electrodes 285 and 286 between times t1 and t2, times t3 and t4, times t5 and t6, and continuing for the time duration of the waveforms. Waveforms 512 and 513 are synchronized and each has a frequency of, for example, 100 K hertz, and a duration of, for example, 0.100 sec. If, for example, the electrodes 285 and 286 are spaced 8 microns apart, this 20-volt differential produces a voltage field of approximately 2.5 million volts per meter, a level of electrical field intensity that can likely neutralize (kill) a bacterium cell. Selected values can be 100,000 volts per meter or greater. The alternating polarities of waveforms 512 and 513 serve to make rapid successive applications of field energy to the targeted pathogen cell between the electrodes. These voltage waveforms are applied each time a total travel time expires for a channel. The applied voltage can be adjusted to a value effective to neutralize a specific pathogen cell. There are many channels in a chamber and there can be many identified pathogen cells in a channel, thereby the electrical energy is applied to potentially a substantial number of the identified pathogen cells.

Continuing reference to FIG. 41C, at step 514, the master controller 434 turns the pump 62 off upon expiration of the pump cycle time. This time is set to be long enough for all of the pathogen cells to flow from the most distant portion of the detection zone to the processing zone. That is, longer than the longest total travel time. When the pump 62 has been turned off, the blood previously in the chambers has been removed and replaced with a new volume of blood for processing. Following step 514 the master controller performs the question step 516 to determine if the total processing time has been reached. If the answer to this question is “NO”, the exit 518 is taken and operations are transferred to step 490 (FIG. 41A) to repeat the overall processing operation. If the answer to the step 516 question is “YES”, exit 520 is taken to step 522. If this exit is taken, the total processing time has elapsed. In step 522, the master controller 434 terminates the processing operation and sends a report thereof to the system controller 14. In step 524 the system controller 14 ends the processing operation and sends a report thereof to its display terminal.

In the above operational description, electrical energy is applied to electrodes in the processing zone to produce an electric field to kill the detected pathogen cells. But, if the processing zone configuration shown in FIGS. 22 and 23 is implemented, there are no insulating layers between the electrodes and the fluid in the channels. In the absence of these insulating layers, the electrodes will apply a voltage differential directly to the blood thereby creating an electrical current through the blood. This current is selected to be of sufficient amplitude to kill the pathogen cells in the processing zone between the electrodes.

One embodiment described above has 30 chambers in a single cassette with a sensor, a chamber processor and memory for each chamber. However, embodiments can be implemented having different configurations which operate as described above. Further, the embodiments can be scaled by the number of chambers and/or flow rate through a chamber and/or data processing speed to provide a desired overall flow rate for blood processing. Non-limiting example embodiments are as follows:

-   -   1. 10 chambers each 2.0 cm×2.0 cm, each chamber having a         corresponding light sensor with a single processor and memory         serving all 10 chambers.     -   2. 10 chambers each 4.0 cm×4.0 cm, each chamber having a         corresponding light sensor, processor and memory.     -   3. 30 chambers 2.0 cm×2.0 cm, each chamber having a         corresponding light sensor, and a single processor and memory         serving all 30 chambers.     -   4. 30 chambers divided into a separate 15 chamber Group A and 15         chamber Group B with a sensor for each chamber and a single         processor and single memory for each group.     -   5. 40 chambers each 2.0 cm×2.0 cm and each chamber having a         corresponding light sensor, and a processor and memory for each         set of 10 chambers.     -   6. 100 chambers 2.0 cm×2.0 cm, each chamber having a         corresponding light sensor, processor and memory.     -   7. 100 chambers 2.0 cm×2.0 cm, each chamber having a         corresponding light sensor and having one memory and one         processor for each 10 chambers.

Although several embodiments of the invention have been illustrated in the accompanying drawings and described in the foregoing Detailed Description, it will be understood that the invention is not limited to the embodiments disclosed but is capable of numerous rearrangements, modifications and substitutions without departing from the scope of the invention. 

What is claimed is:
 1. Apparatus for processing blood which has pathogen cells therein, comprising: at least one chamber having parallel opposed transparent walls, said chamber having an input port for receiving said blood into said chamber and an output port for emptying said blood from said chamber, said chamber having a transparent zone with a plurality of parallel flow channels extending from said chamber input port to a processing zone proximate said chamber output port, a light source for producing collimated light directed toward said transparent zone of said chamber, a light sensor having an array of pixels sensitive to said light, said light sensor positioned on the opposite side of said chamber from said light source, said light sensor for receiving said light which has passed through said walls of said chamber to said light sensor, said light sensor for producing a sensor image of said light received from said light source through said chamber, said sensor image having shadow images therein of said pathogen cells present in said chamber, an electronic memory for storing reference images corresponding to said pathogen cells, a processor coupled to receive said sensor image and said reference images for comparing said shadow images to said reference images and identifying the ones of said shadow images which correspond to one or more of said reference images and for determining the locations in said chamber of the pathogen cells corresponding to the identified shadow images, and a processing zone in said chamber for receiving said pathogen cells corresponding to the identified shadow images in said channels and for applying electrical energy to said received pathogen cells in said processing zone.
 2. Apparatus as recited in claim 1 including a plurality of parallel flow channels in said chamber extending from proximate said chamber input port to proximate said chamber output port through said chamber transparent zone and said chamber processing zone.
 3. Apparatus as recited in claim 2 including a plurality of pairs of electrodes, each said pair of electrodes positioned in a corresponding one of said channels in said processing zone.
 4. Apparatus as recited in claim 3 wherein the electrodes in said pair are positioned on opposing walls of the corresponding channel.
 5. Apparatus as recited in claim 3 including a layer of electrical insulation covering each of said electrodes to electrically isolate the electrode from blood in the corresponding channel.
 6. Apparatus as recited in claim 1 including an electrical driver for applying a voltage differential to each of said pairs of electrodes in response to electrical signals from said processor to produce said electrical energy.
 7. Apparatus as recited in claim 1 including a pump for pumping said blood into said chamber and for driving said blood through said channels in said chamber from said transparent zone to said processing zone.
 8. Apparatus as recited in claim 1 wherein the interior surfaces of said chamber walls are parallel and are spaced apart by not more than 10 microns.
 9. Apparatus as recited in claim 1 wherein said processor is also for producing a travel time from the location of each identified pathogen cell in said transparent zone to said processing zone.
 10. Apparatus for processing blood which has pathogen cells therein, comprising: a cassette having therein a plurality of chambers, said cassette having an input port and an output port for said blood, each said chamber having parallel, transparent opposing walls and each chamber having a chamber input port for receiving said blood and a chamber output port for exiting said blood, each said chamber having a plurality of parallel flow channels extending from said chamber input port to said chamber output port, said cassette having a distribution manifold having an input coupled to said cassette input port and a plurality of outputs coupled respectively to said chamber input ports and a collection manifold having a plurality of input ports coupled respectively to said chamber output ports and an output port coupled to said cassette output port, a light source for producing collimated light directed toward said transparent walls of said chambers, a plurality of light sensors each having an array of pixels sensitive to said light, each said light sensor positioned on the opposite side of a corresponding one of said chambers from said light source, each said light sensor for receiving said light which has passed through said walls of the corresponding chamber to the light sensor, each said light sensor for producing a sensor image of said light received from said light source through the corresponding chamber, each said sensor image having shadow images therein of said pathogen cells present in the corresponding chamber, an electronic memory for storing reference images corresponding to said pathogen cells, a processor coupled to receive said sensor images and said reference images for comparing said shadow images to said reference images and identifying the ones of said shadow images which correspond to one or more of said reference images and for determining the locations in said chamber of the pathogen cells corresponding to the identified shadow images, and a processing zone in each said chamber proximate the output port of the corresponding chamber for receiving said pathogen cells corresponding to said identified shadow images in said chambers.
 11. Apparatus as recited in claim 10 including a plurality of pairs of electrodes in said processing zone for applying electrical energy to said pathogen cells in said processing zone.
 12. Apparatus as recited in claim 11 including a plurality of driver circuits coupled to said plurality of pairs of electrodes for applying a voltage differential to ones of said pairs of electrodes to produce said electrical energy.
 13. Apparatus as recited in claim 11 including a plurality of layers of electrical insulation positioned over said electrodes to electrically isolate said electrodes from blood present in said processing zone of said chamber.
 14. Apparatus as recited in claim 10 wherein said light source, said cassette and said plurality of image sensors are each planar structures positioned in parallel to each other.
 15. Apparatus for processing blood which has pathogen cells therein, comprising: a cassette having an input port and output port for said blood, a plurality of chambers in said cassette, each chamber having an input port and an output port, each said chamber having an identification zone proximate said chamber input port and a processing zone proximate said chamber output port, a distribution manifold in said cassette coupled between said cassette input port and the input ports of said chambers, a collection manifold in said cassette coupled between said chamber output ports and said cassette output port, each said chamber having a plurality of parallel flow channels extending between the chamber input port and the chamber output port, a light source for producing collimated light directed to said chambers, a plurality of light sensors for receiving light from said light source which has passed through said chambers, each of said light sensors corresponding respectively to said chambers, each said light sensor for producing a sensor image having shadow images therein of cells in the corresponding said chamber, an electronic storage for storing reference pathogen cell images, a processor for comparing said shadow images to said reference pathogen cell images to identify and locate said pathogen cells in said chambers, a pump for transferring said blood having said identified pathogen cells therein from said identification zone to said processing zone, and electrodes in said processing zone for applying electrical energy selectively to volumes of said blood containing said identified pathogen cells transferred to said processing zone.
 16. Apparatus as recited in claim 15 including driver circuits coupled to said electrodes and controlled by said processor for applying electrical signals at said electrodes to produce said electrical energy.
 17. Apparatus as recited in claim 15 wherein said electrical signals at said electrodes produce an electrical current through said blood.
 18. Apparatus as recited in claim 15 including a plurality of layers of electrical insulation positioned over said electrodes to electrically isolate said electrodes from said blood present in said processing zone of said chamber wherein said electrical energy to applied to said blood as an electrical field.
 19. Apparatus as recited in claim 15 wherein said plurality of parallel flow channels in each said chamber are formed by a plurality of parallel ridges extending from the chamber input port to the chamber output port and opposing walls of the chamber.
 20. Apparatus as recited in claim 15 wherein said light source, said cassette and said light sensor are each planar structures that are parallel to each other. 